The present application claims priority to Italian Patent Application Serial No. MI99A 002280, filed Nov. 2, 1999.
The subject of the present invention is a perforator device for ribbons of paper in re-reeling machines. As is known, in re-reeling machines there is present a mechanism for obtaining perforation of the paper, the said means consisting of two main elements: a rotating roller which carries, mounted in a helical manner, a plurality of blades, and a counter-roller which carries one or more fixed counterblades.
The presence on the counter-roller of a number of fixed toothed counterblades enables easy and quick changing of the counterblade that is in contact with the rotating blades, and hence of the pattern of the perforation made on the paper.
In fact, the pattern of perforation is determined by the spacing and proportions of the comb-like toothing present on the counterblade. Consequently, to vary the perforation pattern it is necessary to change the pitch and the proportions between the tooth and the compartment of said toothing.
Even though the devices of the type described are able to perform the function for which they are designed, they leave the possibility for a number of interesting and important improvements.
In particular, a problem that necessarily arises with the use of the re-reeling machine is caused by the fact that the wear of the smooth blades of the rotating roller is located in the points that come into contact with the fixed toothed counterblade.
Consequently, when the profile of the toothed counterblade is changed, the points of contact are inevitably changed, so altering the correct interference between the blades and the counterblade.
The purpose of the present invention is therefore to provide a perforator device for ribbons of paper in re-reeling machines which can enable the aforesaid problems to be solved, obtaining better operating features and greater overall efficiency, together with less wear over time.
These and other purposes are achieved by a perforator device for ribbons of paper in re-reeling machines, wherein said re-reeling machine comprising a roller turning and carrying a plurality of smooth perforating blades on helical seats, and a counter roller carrying at least one toothed counterblade, wherein said rotating roller translates with respect to fixed supports; and elastic means for repositioning all said parts.
Advantageously, the device according to the invention enables the point of contact between the blades and the counterblades to be constantly displaced, so causing a uniform wear of the smooth blades.
Further characteristics of the present invention are moreover defined in the subsequent claims.
Further purposes and advantages of the present invention will emerge clearly from the ensuing description and from the annexed drawings, which are provided purely to give an explanatory and non-limiting example, and in which: